Dual temperature curable silicone compositions, methods of manufacture, and articles prepared therefrom

ABSTRACT

Dual temperature curable silicone compositions, articles made from such compositions, and methods for the manufacture and use thereof. In particular, a dual temperature curable silicone composition is manufactured from a composition comprising a vinyl silicone; a silicone hydride-containing crosslinker, a platinum-containing catalyst; and a peroxide catalyst.

BACKGROUND

This disclosure relates generally to dual temperature curable siliconecompositions, articles made from such compositions, and methods for themanufacture and use thereof.

Silicone compositions are used in a variety of technologies. There is aneed for silicone compositions that have improved properties such asease of formulation, and flexibility in tailoring the compositionproperties for a desired use. There is a particular need forcompositions having improved handling characteristics before cure of thecomposition is complete.

SUMMARY

Disclosed herein is a dual temperature curable silicone composition,comprising 100 parts by weight of a vinyl silicone; 0.05-10 parts byweight of a silicone hydride-containing crosslinker; 0.5-5 parts byweight of a platinum-containing catalyst; and 0.2-5 parts by weight of aperoxide catalyst. Also disclosed herein is a method of fully curing adual temperature curable silicone composition, comprising providing asilicone composition comprising a vinyl silicone; a siliconehydride-containing crosslinker; a platinum-containing catalyst; and aperoxide catalyst; exposing the silicone composition to a firsttemperature to activate the platinum catalyst but not the peroxidecatalyst, to form a semi-cured composition; and heating the semi-curedcomposition to a second temperature sufficient to activate the peroxidecatalyst, to form a fully cured composition. Also disclosed herein is amethod of semi-curing a dual temperature curable silicone composition,comprising: providing a dual temperature curable silicone compositioncomprising a vinyl silicone; a silicone hydride-containing crosslinker;a platinum-containing catalyst; and a peroxide catalyst; exposing thesilicone composition to a first temperature to activate the platinumcatalyst but not the peroxide catalyst to form a semi-cured composition.Also disclosed herein is a method of forming an article comprisingshaping a silicone composition comprising vinyl silicone; a siliconehydride-containing crosslinker; a platinum-containing catalyst; and aperoxide catalyst to form an uncured article; exposing the uncuredarticle to a first temperature to activate the platinum catalyst but notthe peroxide catalyst, to provide a semi-cured article; and heating thesemi-cured article to a second temperature sufficient to activate theperoxide catalyst, to form a fully cured article.

The above described and other features are exemplified by the followingdetailed description.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Described herein are dual temperature curable silicone compositions,articles made from such compositions, and methods for the manufactureand use thereof. In particular, the inventors hereof have developedsilicone compositions that can be partially or semi-cured at a lowertemperature, and fully cured at a higher temperature. In particular, thedual temperature curable silicone composition is manufactured from acomposition comprising a vinyl silicone; a silicone hydride-containingcrosslinker; a platinum-containing catalyst; and a peroxide catalyst. Afirst, lower cure temperature activates the platinum-containingcatalyst, and a second, higher cure temperature activates the peroxidecatalyst and fully cures the composition. In an especially advantageousfeature, the compositions can be shaped, semi-cured, and then stored inthe semi-cured form and fully cured at a later time. For example, use ofa semi-cure provides an article that can be easily repositioning duringsubsequent manufacturing steps, for example before lamination. Thus,semi-cure can be used to reduce tack of the composition. The greenstrength of the semi-cure composition can be greater than the uncuredcomposition. The semi-cure can also increase the “uncured bond strength”between the silicone composition and an adherend.

The methods of curing a dual temperature curable silicone compositionare useful not only for forming layers and coatings, but also forcomposite materials. The dual temperature curable silicone compositionscan be used as an adhesive, for example to bond to one or moresubstrates or substances such as the silicone composition itself, ametal, or a polymer such as polyimide. It has been found that the dualtemperature curing system described provides flexibility in processing,such as the ability to use the semi-cured form to bond to a substrateand then continuing to the fully cured form which can bond to adifferent substance or the composition itself. In an embodiment, thesemi-cured form can bond to polyimide or another substrate, for example.In an embodiment, the fully cured form can bond to a metal foil.

The dual temperature curable silicone compositions, articles preparedtherefrom, and methods of manufacturing are further illustrated by thefollowing embodiments, which are non-limiting.

The dual temperature curable silicone composition comprises, based onthe total weight of the composition: 100 parts by weight of a vinylsilicone; 0.05-10 parts by weight of a silicon hydride-containingcrosslinker; 0.5-5 parts by weight of a platinum-containing catalyst;and 0.2-5 parts by weight of a peroxide catalyst. The viscosity of thedual temperature curable silicone composition can vary widely beforecure, for example 10,000 mPa·sec at 25° C. to 500,000 mPa·sec at 25° C.

The vinyl silicone is siloxane having one or more vinyl groups orsubstituted vinyl group bonded to a silicon atom. As used herein, avinyl group is a group having the formula —CH═CH₂, and a “substitutedvinyl group” has the formula —CH═CR₂, where the R groups can beindependently hydrogen or C₁₋₆ alkyl groups. The vinyl silicone cancomprise a polydialkyl siloxane having more than one vinyl group orsubstituted vinyl group bonded to silicon. In an embodiment, the vinylsilicone comprises a polydiorganosiloxane functionalized with a terminal—Si(R¹R²)—CH═CH₂ group, wherein R¹ and R² are each independentlyhydrogen or C₁-C₆ alkyl groups, preferably a terminal —Si(Me)₂-CH═CH₂group, for example a dimethylvinyl-terminated dimethylsiloxane. A vinylgroup or substituted vinyl group can be present at one or both terminiof the vinyl silicone. Alternatively, or in addition, the vinyl orsubstituted vinyl group can be bonded to a non-terminal silicon atom ofthe vinyl silicone.

In an embodiment, the vinyl silicone is of Formula (I)

R^(B)[Si(R¹R²)—O]—[(Si(R³R⁴)—O)]_(n)—[Si(R⁵R⁶)—O)]_(m)—Si(R¹R²)—R^(A)  (FormulaI)

wherein n has an average value of 1 to 200, preferably 50 to 150, morepreferably 100 to 150; m is 0 or has an average value of 1 to 20,000,preferably 10,000 to 20,000, more preferably 10,000 to 15,000; R^(A),R^(B), R¹, R², R³, R⁴, R⁵ and R⁶ are each independently phenyl or C₁-C₆alkyl; and at least one of R^(A), R^(B), R³ or R⁴ has the formula—CH═CR^(F)R^(G), where R^(F) and R^(G) are each independently hydrogenor C₁-C₆ alkyl. In an embodiment, m and n are selected to provide aviscosity of the vinyl silicone of 10,000 mPa·sec to 500,000 mPa·sec at25° C. In Formula (I), the R^(A), R^(B), R¹, R², R³, R⁴, R⁵, and R⁶groups that are not vinyl can be an alkyl group such as methyl, ethyl,or propyl. Preferably, the R^(A), R^(B), R¹, R², R³, R⁴, R⁵ and R⁶groups in Formula (I) that are not vinyl are methyl. In an embodiment,in Formula (I), R¹ and R² are both methyl groups. The vinylconcentration in the vinyl silicone can be 0.001 to 1 mole percent.

The silicon hydride-containing crosslinker includes one or more groupscontaining a hydrogen atom bonded to a silicon atom (—Si—H). In anembodiment, the silicone hydride-containing crosslinker is a compoundcomprising silicon-bonded hydride groups at one or more terminal endsthereof. Alternatively, or in addition, one or more silicon-bondedhydride groups can be present along the backbone of the crosslinker. Inan embodiment, the silicone hydride-containing crosslinker comprises twoor more silicon-bonded hydrogen atoms, or three or more silicon-bondedhydrogen atoms. In an embodiment, the silicone hydride-containingcrosslinker contains two or three silicon-bonded hydrogen atoms, and upto eight silicon-bonded hydrogen atoms per molecule.

In an embodiment, the silicone hydride-containing crosslinker is ofFormula (II):R^(D)—Si(R⁷R⁸)O—[Si(R⁹R¹⁰)—O)]_(x)—[Si(R¹¹R¹²)—O)]_(y)—Si(R¹³R¹⁴)—R^(E)(Formula II) wherein at least one of R^(D), R^(E), R⁷, R⁸, R⁹, R¹⁰, R¹¹,R¹², R¹³ and R¹⁴ is hydrogen; and the others of R^(D), R^(E), R⁷, R⁸,R⁹, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ are each independently phenyl or C₁-C₆alkyl; x has an average value of 1 to 300, preferably 100 to 300, morepreferably 150 to 250; y is 0 or has an average value of 1 to 300,preferably 100 to 300, more preferably 150 to 250.

In an embodiment, in the silicon hydride-containing crosslinker ofFormula II, both of R^(D) and R^(E) are hydrogen and R⁷, R⁸, R⁹, R¹⁰,R¹¹, R¹², R¹³, and R¹⁴ are phenyl or methyl, preferably methyl. In anembodiment, in the silicon hydride-containing crosslinker of Formula II,y is 0; both of R^(D) and R^(E) are methyl; R⁹ is hydrogen and R⁷, R⁸,R¹⁰, R¹³, and R¹⁴ are methyl. In an embodiment, in the siliconhydride-containing crosslinker of Formula II, both of R^(D) and R^(E)are methyl; R⁹ is hydrogen and R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹³, and R¹⁴ aremethyl. Further, in Formula (II), x and y are adjusted to provide thedesired number of silicon hydride groups and the desired viscosity inthe silicon hydride-containing crosslinker. Generally, any siliconehydride-containing crosslinker useful in heat-cure systems can be usedin the compositions described here. Examples of such siliconehydride-containing crosslinkers include those available from commercialsources.

In some embodiments, the silicone hydride-containing crosslinker has ahydride content ranging from 0.02 to 10 percent by weight and aviscosity ranging from 10 to 10,000 centipoise at 25° C.

The platinum-containing catalyst is any suitable platinum-containingcatalyst. In an embodiment, the platinum-containing catalyst comprises aPt(0) complex, a Pt(II) complex, a Pt(IV) complex or a combinationcomprising at least one of the foregoing. The platinum-containingcatalyst can be a finely divided metallic platinum, platinum on a finelydivided carrier such as alumina, compounds of platinum such aschloroplatinic acid, or complexes of platinum.

Some examples of platinum-containing catalysts comprising a Pt(0)complex include: bis-(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum (0); (2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane)platinum(0); ethylenebis(triphenylphosphine)platinum(0),bis(tri-tert-butylphosphine) platinum(0); andtetrakis(triphenylphosphine) platinum(0). Some examples ofplatinum-containing catalysts comprising a Pt(II) complex include:dimethyl (1,5-cyclooctadiene)platinum(II);trans-dichlorobis(triethylphosphine) platinum(II);dichlorobis(ethylenediamine) platinum(II); dichloro(1,5-cyclooctadiene)platinum(II); platinum(II) chloride; platinum(II) bromide; platinum(II)iodide; trans-platinum(II)diamine dichloride;dichloro(1,2-diaminocyclohexane) platinum(II); and ammoniumtetrachloroplatinate(II). Some examples of platinum-containing catalystscomprising a Pt(IV) complex include: dihydrogen hexachloroplatinate (IV)hexahydrate; platinum(IV) oxide hydrate; and ammoniumhexachloroplatinate(IV). The platinum-containing catalyst can be in theform of a dispersion, a powder, or a solubilized complex.

The platinum-containing catalyst is selected to be activated at a lowertemperature than the peroxide catalyst. In an embodiment, theplatinum-containing catalyst is activated at a temperature at least 25°C. lower, or at least 40° C. lower, at least 50° C. lower, or at least60° C. lower than the peroxide catalyst. In an embodiment, theplatinum-containing catalyst is activated at room temperature,preferably between 18-28° C., more preferably between 20-26° C.

A wide variety of peroxide catalysts can be used, for example aninorganic or organic peroxide (such as an aliphatic, aromatic, or mixedaliphatic-aromatic peroxide), or a combination comprising at least oneof the foregoing. In an embodiment, the peroxide catalyst comprisesbenzoyl peroxide, di-t butyl peroxide, 2,4-dichlorobenzoyl peroxide, or2,5-bis(t-butylperoxy)-2,5-dimethylhexane. In an embodiment, theperoxide catalyst is 2,4-dichlorobenzoyl peroxide.

The relative amount of platinum-containing catalyst and peroxidecatalyst in the curable silicone composition are selected based on thereactivity of the components and to provide the desired cure state,including semi-cured and fully cured state, and the desired curingconditions, including temperature and desired length of cure of eachcure step. For example, the platinum-containing catalyst and peroxidecatalyst can be present in a weight percent ratio of 0.001:1 to 1:1, forexample 0.005:1 to 0.8:1, or 0.01:1 to 0.5:1.

In an embodiment, the dual temperature curable silicone compositionfurther comprises one or more components known for use in theformulation of curable silicones. For example, the dual temperaturecurable silicone compositions can further comprise a solvent. In anembodiment, the solvent comprises one or more of an organic solvent andwater. In an embodiment, the solvent is one or more organic solvents.The solvent can be any suitable solvent or solvent mixture that allowsthe desired reactions to occur, for example an alcohol (e.g., a C₁-C₄alcohol), water, an aromatic solvent such as xylene, or a combinationcomprising the foregoing. In an embodiment, the alcohol is present in anamount from 1-100 parts by weight, based on the total weight of thenon-solvent components of the composition; the water is present from1-20 parts by weight, based on the total weight of the non-solventcomponents of the composition; and the aromatic solvent is present from200-2000 parts by weight based on the total weight of the non-solventcomponents of the composition.

Other components or additives, such as fillers, inhibitors, dispersingaids, adhesion promoters, dyes, plasticizers, heat stabilizers,pigments, antioxidants, or the like, or a combination comprising atleast one of the foregoing can be present in the curable siliconecompositions. In an embodiment, the dual temperature curable siliconecomposition further comprises a heat stabilizer. Heat stabilizers can beused to improve the heat resistance of cured silicone compositions. Theamount of heat stabilizer used is sufficient to provide the desiredlevel of heat stability, but not so high to cause undesirable physicalproperties of the composition. In an embodiment, the heat stabilizer ispresent in the curable silicone composition at 0.05 to 10 parts byweight of the composition. Heat stabilizers are known in the art, andcan be, for example, carbon black, calcium carbonate, a metal oxide suchas iron oxide, zinc oxide, or a combination comprising at least one ofthe foregoing.

The compositions can be formulated by any suitable means, includingstandard mixing equipment or by hand. A convenient method for preparingthe curable silicone compositions is mixing the different components tohomogeneity and removing air by degassing under vacuum. The compositionscan then be stored until use. Alternatively, the compositions can bemixed separately into an A and B formulation for mixing immediatelyprior to use. For example the vinyl siloxane can be stored separatelyfrom the platinum catalyst and silicon-hydride containing component.

In a method of use of the curable silicone composition, the compositionis heated or otherwise exposed to a first temperature sufficient toactivate the platinum-containing catalyst for a sufficient amount oftime to achieve the desired level of curing to form a semi-curedcomposition. In an embodiment, exposing refers to application of heat orheating, including allowing the composition or article to be at roomtemperature. In an embodiment, the first temperature is roomtemperature. In an embodiment, the semi-cured composition is partiallycured by exposing the composition to room temperature for a sufficientamount of time for the desired level of cure to occur. In an embodiment,the first temperature is 21° C. to below 100° C. In another embodiment,the first temperature is 21° C. to below 50° C. In an embodiment, thefirst temperature is held for 10 to 240 minutes, or from 100 to 600minutes. The specific temperatures and times depend on the particularplatinum-containing and organic catalysts selected, the reactivity ofthe components of the curable composition, and the degree of curedesired. As used herein, “semi-cured” includes a wide variety of curedstates, provided that the cure is not complete. For example, a“semi-cured” composition can be a silicone composition wherein 5 to 85%of the reactive vinyl groups have been reacted, or 10 to 70% of thereactive vinyl groups have reacted, or 10 to 50% of the vinyl groupshave reacted. In a preferred embodiment, the degree of cure is selectedto provide a semi-cured composition that is B-staged as that term isused in the art. Thus, in a preferred embodiment, the uncuredcompositions are shaped, for example cast or calendered to form a layer;and then partially cured to provide mechanical integrity to the shape sothat it can be readily manipulated for storage or subsequent use, i.e.,subsequent manufacturing steps. Such steps can include storage betweenrelease layers, or further layering for, e.g., lamination to otherlayers.

After such steps (if any), the semi-cured composition is then fullycured by heating the semi-cured composition to a second temperaturesufficient to activate the peroxide catalyst. In an embodiment, thesecond temperature is 70° C. to 250° C., for example 100° C. to 250° C.,for example 125° C. to 220° C., or 130° C. to 200° C. The second curecan be conducted, for example, for 10 to 300 minutes. Methods of heatinga silicone composition and curing a silicone composition includepress-curing, hot-air curing, oven baking, and lamination.

Thus, in some embodiments a method of semi-curing or fully curing a dualtemperature curable silicone composition comprises providing a siliconecomposition comprising a vinyl silicone, a silicone hydride-containingcrosslinker, a platinum-containing catalyst, and a peroxide catalyst;exposing the uncured composition to a first temperature (e.g., below100° C., preferably below 50° C.) to activate the platinum catalyst butnot the peroxide catalyst, to form a semi-cured composition. Heating thesemi-cured composition to a second temperature sufficient to activatethe peroxide catalyst forms a fully cured composition. In an embodiment,the method further comprises forming the uncured or semi-cured siliconecomposition into a desired shape. For example, the uncured compositioncan be shaped, and semi-cured sufficiently to retain the shape(B-staged). Alternatively, the uncured composition can be semi-cured;and then shaped prior to full cure, which also provides a B-stagearticle.

Specifically, in some embodiments, a method of forming a semi-curedarticle comprises providing a silicone composition comprising a vinylsilicone, a silicone hydride-containing crosslinker, aplatinum-containing catalyst, and a peroxide catalyst; exposing theuncured composition to a first temperature (e.g., below 100° C.,preferably below 50° C.) to activate the platinum catalyst but not theperoxide catalyst, to provide a semi-cured composition; and shaping thesemi-cured composition to provide a shaped, semi-cured article. Theshaping can be by casting or calendering onto a substrate or a releaselayer.

In other embodiments, a method of forming a semi-cured article comprisesshaping a silicone composition comprising a vinyl silicone, a siliconehydride-containing crosslinker, a platinum-containing catalyst, and aperoxide catalyst to form a shaped, uncured composition; and exposingthe shaped uncured composition to a first temperature (e.g., below 100°C., preferably below 50° C., or storing at room temperature) to activatethe platinum catalyst but not the peroxide catalyst, to provide ashaped, semi-cured article. The shaping can be by casting or calenderingonto a substrate or a release layer. Optionally, the semi-cured articlecan subjected to an additional manufacturing step, e.g., layering withanother layer.

In yet other embodiments, a method of forming an article comprisesproviding a silicone composition comprising a vinyl silicone, a siliconehydride-containing crosslinker, a platinum-containing catalyst, and aperoxide catalyst; exposing the uncured composition to a firsttemperature (e.g., below 100° C., preferably below 50° C.) to activatethe platinum catalyst but not the peroxide catalyst, to provide asemi-cured composition; shaping the semi-cured composition (e.g., bycasting or calendering onto a substrate or a release layer) to provide asemi-cured article; and heating the semi-cured composition to a secondtemperature sufficient to activate the peroxide catalyst, to form afully cured article. Optionally, the semi-cured article can subjected toan additional manufacturing step, e.g., layering with another layer; andthe second temperature can be achieved by lamination.

In still other embodiments, a method of forming an article comprisesshaping a silicone composition comprising a vinyl silicone, a siliconehydride-containing crosslinker, a platinum-containing catalyst, and aperoxide catalyst to form an uncured article; exposing the uncuredarticle to a first temperature (e.g., below 100° C., preferably below50° C.) to activate the platinum catalyst but not the peroxide catalyst,to provide a semi-cured article; and heating the semi-cured article to asecond temperature sufficient to activate the peroxide catalyst, to forma fully cured article. Optionally, the semi-cured article can subjectedto an additional manufacturing step, e.g., layering with another layer;and the second temperature can be achieved by lamination.

The semi-cured and fully cured silicone compositions made by the methodsdescribed can be used in a variety of applications. In an embodiment,the semi-cured or fully cured composition provides adhesion to twoadherends. For example, the uncured composition can be cast orcalendered onto a substrate (i.e., a first adherend) to form a layer,semi-cured, and then contacted with the second adherend, and thecomposition fully cured, for example by lamination.

In some embodiments, a primer can be used to enhance adhesion to asubstrate or first adherend. Such primers are known, and include, forexample, multi-functional compounds reactive with the silicone and withthe substrate, for example vinyl group- or substituted vinylgroup-containing silanes. Such compounds include, for example, a vinyltris(alkoxyalkoxy)silane. In an embodiment, the vinyltris(alkoxyalkoxy)silane is present in an amount of 2-20 parts byweight, based on the total weight of the composition. In an embodiment,the vinyl tris(alkoxyalkoxy)silane is vinyltris[(C₁-C₆alkoxy)(C₁-C₆alkoxy)]silane. In an embodiment, the vinyltris(alkoxyalkoxy)silane is vinyl tris(2-methoxyethoxy) silane. Theprimers can be applied by methods known in the art, for example dippingor coating. In some embodiments, any primer layer has a thickness from 1μm (0.04 mil) to 2000 μm (80 mil). The thickness of each of the primerlayers can vary depending on the adherends. For example the primerlayers can have a thickness of 1 to 2,000 micrometers (μm) (0.04 to 80mil), and in some embodiments the primer layers can have a thickness of2 to 1000 μm (0.08 to 40 mil), or 2 to 100 μm (0.08 to 4 mil).

The invention is further illustrated by the following examples, whichare non-limiting.

EXAMPLES

Several silicone formulations were prepared. In general, the componentslisted for each formulation listed were mixed and underwent a firstcuring step to form a semi-cured composition. If desired, a secondcuring step was performed to form a cured composition. The semi-curedand cured compositions were analyzed to measure various compositioncharacteristics.

Example A. Comparative Formulation

The formulation listed in Table 1 was prepared and cured according tothe procedure above.

TABLE 1 Nominal parts Component description Supplier name SupplierDesignation CAS Number by weight Methyl vinyl silicone base MPM Silplus50MP 68083-18-1 100 2,4-Dichlorobenzoyl peroxide Akzo Nobel PD-50S133-14-2 1.67 dispersion Heat Stabilizer Dow Corning HT-1 N/A 1

Example B. Comparative Formulation

The formulation listed in Table 2 was prepared and cured according tothe procedure above.

TABLE 2 Nominal Parts Component description Supplier name SupplierDesignation CAS Number by weight Pt cure silicone Wacker Elastosil R-50100 Pt Catalyst Wacker Elastosil AUX PT1 N/A 1.5 Heat Stabilizer DowCorning HT-1 N/A 1

Example C. Comparative Formulation

The formulation listed in Table 3 was prepared and cured according tothe procedure above.

TABLE 3 Nominal Parts Component description Supplier name SupplierDesignation CAS Number by weight Pt cure silicone Wacker Elastosil R-50100 Pt Catalyst Wacker Elastosil AUX PT1 N/A 1.5 Siliconehydride-containing Dow Corning XL2 N/A 0.8 crosslinker Heat StabilizerDow Corning HT-1 N/A 1

Example D. Silicone Formulation

A formulation having a composition listed in Table 4 was prepared andcured according to the procedure above.

TABLE 4 Parts by weight Component description Supplier name SupplierDesignation CAS Number range Methyl vinyl silicone base BlueStar MF940U68083-18-1 100 Pt Catalyst Dispersion Wacker Elastosil AUX PT1 N/A 0.5-52,4-Dichlorobenzoyl peroxide Akzo Nobel PD-50S 133-14-2 0.2-5 dispersionSilicone hydride-containing Dow Corning XL2 N/A 0.05-10 crosslinker HeatStabilizer Dow Corning HT-1 N/A 0.05-10

Primer/Dispersion Examples

Example primer/dispersion formulations are listed in Tables 5-7.

Example E. Comparative Example

A formulation having a composition listed in Table 5 was prepared. Theformulation was then tested. The formulation did not provide a desiredcured bond strength.

TABLE 5 Supplier Nominal Parts by weight Component description Suppliername Designation CAS Number allowable range Vinyl Silicone Dow CorningRBB-2390-30 68083-18-1 100 2,4-Dichlorobenzoyl peroxide Akzo NobelPD-50S 133-14-2 1-5  Vinyltris(2- EVONIK Dynasylan 1067-53-4 2-20methoxyethoxy)silane VTMOEO Xylene 1330-20-7 200-2000

Example F. Comparative Example

A formulation having a composition listed in Table 6 was prepared. Theformulation was then tested. The formulation provided a desired curedbond strength, but the formulation did not provide sufficient uncuredbond strength for subsequent manufacturing.

TABLE 6 Nominal Parts by weight Component description Supplier nameSupplier Designation CAS Number allowable range Vinyl Silicone DowCorning RBB-2390-30 68083-18-1 100 2,4-Dichlorobenzoyl peroxide AkzoNobel PD-50S 133-14-2 1-5  Vinyltris(2- EVONIK Dynasylan 1067-53-4 2-20methoxyethoxy)silane VTMOEO Isopropyl alcohol 67-63-0  1-100 Water7732-18-5 1-20 Xylene 1330-20-7 200-2000

Example G. Primer Formulation

A formulation having a composition listed in Table 7 was prepared. Theformulation demonstrated a desired cured and uncured bond strength.

TABLE 7 Nominal Parts by weight Component description Supplier nameSupplier Designation CAS Number allowable range Vinyl Silicone DowCorning RBB-2390-30 68083-18-1 100 Pt Catalyst Wacker Elastosil AUX PT1N/A 1-10 2,4-Dichlorobenzoyl Akzo Nobel PD-50S 133-14-2 1-5  peroxideVinyltris(2- EVONIK Dynasylan VTMOEO 1067-53-4 2-20 methoxyethoxy)silaneIsopropyl alcohol 67-63-0  1-100 Water 7732-18-5 1-20 Xylene 1330-20-7200-2000 Silicone hydride fluid Dow Corning XIAMETER ® MHX-  1-100 1107FLUID 30CS

Set forth below are specific embodiments of dual temperature curablesilicone compositions, methods of partially or fully curing the siliconecompositions, and methods of forming articles.

Embodiment 1

A dual temperature curable silicone composition, comprising:

100 parts by weight of a vinyl silicone;

0.05-10 parts by weight of a silicone hydride-containing crosslinker;

0.5-5 parts by weight of a platinum-containing catalyst; and

0.2-5 parts by weight of a peroxide catalyst.

Embodiment 2

The composition of Embodiment 1, wherein the vinyl silicone is ofFormula (I):

R^(B)[Si(R¹R²)—O]—[(Si(R³R⁴)—O)]_(n)—[Si(R⁵R⁶)—O)]_(m)—Si(R¹R²)—R^(A)  (FormulaI)

wherein

n has an average value of 1 to 200, preferably 50 to 150, morepreferably 100 to 150;

m is 0 or has an average value of 1 to 20,000, preferably 10,000 to20,000, more preferably 10,000 to 15,000;

R^(A), R^(B), R¹, R², R³, R⁴, R⁵ and R⁶ are each independently a C₁-C₆alkyl group; and at least one of R^(A), R^(B), R³ and R⁴ has the formula—CH═CR^(F)R^(G), where R^(F) and R^(G) are each independently hydrogenor a C₁-C₆ alkyl group.

Embodiment 3

The composition of Embodiment 2, wherein at least one of R^(A), R^(B),R³ and R⁴ is —CH═CH₂.

Embodiment 4

The composition of Embodiment 2, wherein at least one of R^(A) or R^(B)is —CH═CH₂.

Embodiment 5

The composition of Embodiment 4, wherein R¹ and R² are both methylgroups.

Embodiment 6

The composition of any one or more of the preceding Embodiments, whereinthe vinyl silicone comprises a polydiorganosiloxane functionalized witha terminal —Si(Me)₂-CH═CH₂ group.

Embodiment 7

The composition of any one or more of the preceding Embodiments, whereinthe vinyl silicone comprises a dimethylvinyl-terminateddimethylsiloxane.

Embodiment 8

The composition of any one or more of the preceding Embodiments, whereinthe silicone hydride-containing crosslinker is of Formula (II):

R^(D)—Si(R⁷R⁸)O—[Si(R⁹R¹⁰)—O)]_(x)—[Si(R¹¹R¹²)—O)]_(y)—Si(R¹³R¹⁴)—R^(E)  (FormulaII)

wherein

at least one of R^(D), R^(E), R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ ishydrogen, and the others of R^(D), R^(E), R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³and R¹⁴ are each independently hydrogen, or C1-C6 alkyl;

x has an average value of 1 to 300, preferably 100 to 300, morepreferably 150 to 250;

y is 0 or has an average value of 1 to 300, preferably 100 to 300, morepreferably 150 to 250.

Embodiment 9

The composition of Embodiment 8, wherein both of R^(D) and R^(E) arehydrogen and R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, and R¹⁴ are methyl.

Embodiment 10

The composition of Embodiment 8, wherein y is 0; both of R^(D) and R^(E)are methyl; R⁹ is hydrogen and R⁷, R⁸, R¹⁰, R¹³, and R¹⁴ are methyl.

Embodiment 11

The composition of Embodiment 8, wherein both of R^(D) and R^(E) aremethyl; R⁹ is hydrogen and R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ aremethyl.

Embodiment 12

The composition of any one or more of the preceding Embodiments, whereinthe silicone hydride-containing crosslinker comprises two or moresilicon-bonded hydrogen atoms.

Embodiment 13

The composition of any one or more of the preceding Embodiments, whereinthe platinum-containing catalyst comprises a Pt(0) complex, a Pt(II)complex, a Pt(IV) complex, or a combination comprising at least one ofthe foregoing.

Embodiment 14

The composition of any one or more of the preceding Embodiments, whereinthe peroxide catalyst comprises an organic peroxide; an aliphaticperoxide; an aromatic peroxide; an organic hydroperoxide; or acombination comprising at least one of the foregoing.

Embodiment 15

The composition of Embodiment 14, wherein the peroxide catalystcomprises benzoyl peroxide; di-t butyl peroxide; 2,4-dichlorobenzoylperoxide; or 2,5-bis(t-butylperoxy)-2,5-dimethylhexane.

Embodiment 16

The composition of Embodiment 15, wherein the peroxide catalyst is2,4-dichlorobenzoyl peroxide.

Embodiment 17

The composition of any one or more of the preceding Embodiments, whereinthe platinum-containing catalyst and peroxide catalyst are present in aweight percent ratio of 0.001:1 to 1:1.

Embodiment 18

The composition of any one or more of the preceding Embodiments, furthercomprising a solvent.

Embodiment 19

The composition of any one or more of the preceding Embodiments, furthercomprising an additive, preferably a heat stabilizer.

Embodiment 20

A method of fully curing a dual temperature curable siliconecomposition, comprising:

providing a silicone composition of any one or more of the precedingEmbodiments;

exposing the silicone composition to a first temperature to activate theplatinum catalyst but not the peroxide catalyst, to form a semi-curedcomposition; and

heating the semi-cured composition to a second temperature sufficient toactivate the peroxide catalyst, to form a fully cured composition.

Embodiment 21

The method of Embodiment 20, wherein the first temperature is below 100°C., and the second temperature is 70° C. to 200° C., provided that thesecond temperature is higher than the first temperature.

Embodiment 22

The method of any one or more of Embodiments 20 to 21, furthercomprising forming the semi-cured or fully cured silicone compositioninto a desired shape.

Embodiment 23

A fully-cured silicone composition, made by the method of any one ormore of Embodiments 20 to 22.

Embodiment 24

A method of semi-curing a dual temperature curable silicone composition,comprising:

providing a dual temperature curable silicone composition comprising avinyl silicone; a silicone hydride-containing crosslinker; aplatinum-containing catalyst; and a peroxide catalyst;

exposing the silicone composition to a first temperature to activate theplatinum catalyst but not the peroxide catalyst to form a semi-curedcomposition.

Embodiment 25

The method of Embodiment 24, wherein the first temperature is below 100°C., preferably below 50° C., or 21° C. to 25° C.

Embodiment 26

The method of any one or more of Embodiments 24 to 25, furthercomprising forming the curable composition or the semi-cured compositioninto a desired shape.

Embodiment 27

A semi-cured silicone composition, made by the method of any one or moreof Embodiments 24 to 25.

Embodiment 28

The composition of Embodiment 23 or 27, wherein the composition providesadhesion to a substrate.

Embodiment 29

A method of forming a semi-cured article comprising:

providing the silicone composition of any one or more of Embodiments 1to 19;

exposing the uncured composition to a first temperature to activate theplatinum catalyst but not the peroxide catalyst, to provide a semi-curedcomposition; and

shaping the semi-cured composition to provide a shaped, semi-curedarticle.

Embodiment 30

A method of forming a semi-cured article comprising:

shaping the silicone composition of any one or more of Embodiments 1 to19; and

exposing the shaped uncured composition to a first temperature toactivate the platinum catalyst but not the peroxide catalyst, to providea shaped, semi-cured article.

Embodiment 31

A method of forming an article comprising:

providing the silicone composition of any one or more of Embodiments 1to 19;

exposing the uncured composition to a first temperature to activate theplatinum catalyst but not the peroxide catalyst, to provide a semi-curedcomposition;

shaping the semi-cured composition to provide a semi-cured article; andheating the semi-cured composition to a second temperature sufficient toactivate the peroxide catalyst, to form a fully cured article.

Embodiment 32

A method of forming an article comprising:

shaping the silicone composition of any one or more of Embodiments 1 to19 to form an uncured article;

exposing the uncured article to a first temperature to activate theplatinum catalyst but not the peroxide catalyst, to provide a semi-curedarticle; and

heating the semi-cured article to a second temperature sufficient toactivate the peroxide catalyst, to form a fully cured article.

Embodiment 33

The method of any one or more of Embodiments 29 to 32, wherein the firsttemperature is below 100° C., and the second temperature is 70° C. to200° C., provided that the second temperature is higher than the firsttemperature.

Embodiment 34

The method of any one or more of Embodiments 29 to 33, wherein theshaping comprises casting or calendering to form a layer.

Embodiment 35

The method of any one or more of Embodiments 29 to 34, furthercomprising forming the layer on a substrate, wherein the substrate hasbeen treated with a primer, preferably a vinyl tris(alkoxyalkoxy)silane.

Embodiment 36

The method of Embodiment 35, wherein the vinyl tris(alkoxyalkoxy)silaneis present in an amount of 2-20 parts by weight.

Embodiment 37

The method of Embodiment 36, wherein the vinyl tris(alkoxyalkoxy)silaneis vinyl tris[(C₁-C₆ alkoxy C₁-C₆ alkoxy)]silane.

Embodiment 38

The method of Embodiment 37, wherein the vinyl tris(alkoxyalkoxy)silaneis vinyl tris(2-methoxyethoxy) silane.

Embodiment 39

The method of any one or more of Embodiments 29 to 38, wherein thesecond temperature is achieved by laminating the article.

In general, the invention may alternatively comprise, consist of, orconsist essentially of, any appropriate components herein disclosed. Theinvention may additionally, or alternatively, be formulated so as to bedevoid, or substantially free, of any components, materials,ingredients, adjuvants or species used in the prior art compositions orthat are otherwise not necessary to the achievement of the functionand/or objectives of the present invention.

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are independently combinable with each other. “Combination” isinclusive of blends, mixtures, alloys, reaction products, and the like.Furthermore, unless otherwise specified, the terms “first,” “second,”and the like, herein do not denote any order, quantity, or importance,but rather are used to denote one element from another. The terms “a”and “an” and “the” herein do not denote a limitation of quantity, andare to be construed to cover both the singular and the plural, unlessotherwise indicated herein or clearly contradicted by context. “Or”means “and/or” unless clearly stated otherwise. It is to be understoodthat the described elements may be combined in any suitable manner inthe various embodiments. The endpoints of all ranges directed to thesame component or property are inclusive of the endpoints, areindependently combinable, and include all intermediate points andranges. Unless defined otherwise, technical and scientific terms usedherein have the same meaning as is commonly understood by one of skillin the art to which this invention belongs. Compounds are describedusing standard nomenclature. For example, any position not substitutedby any indicated group is understood to have its valency filled by abond as indicated, or a hydrogen atom. A dash (“-”) that is not betweentwo letters or symbols is used to indicate a point of attachment for asubstituent. For example, —CHO is attached through carbon of thecarbonyl group.

The term “alkyl” means branched or straight chain, unsaturated C₁₋₃₀hydrocarbon groups e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl,s-butyl, t-butyl, n-pentyl, s-pentyl, n- and s-hexyl, n- and s-heptyl,and, n- and s-octyl. “Alkenyl” means a straight or branched chain,monovalent hydrocarbon group having at least one carbon-carbon doublebond (e.g., ethenyl (—HC═CH₂)). “Alkoxy” means an alkyl group that islinked via an oxygen (i.e., alkyl-O—), for example methoxy, ethoxy, andsec-butyloxy groups. “Alkylene” means a straight or branched chain,saturated, divalent aliphatic hydrocarbon group (e.g., methylene (—CH₂—)or propylene (—(CH₂)₃—)). “Substituted” means that the compound or groupis substituted with at least one (e.g., 1, 2, 3, or 4) substituentsindependently selected from a C₁₋₉ alkoxy, a C₁₋₉ haloalkoxy, a nitro(—NO₂), a cyano (—CN), a C₁₋₆ alkyl sulfonyl (—S(═O)₂-alkyl), a C₆₋₁₂aryl sulfonyl (—S(═O)₂-aryl), a thiol (—SH), a thiocyano (—SCN), a tosyl(CH₃C₆H₄SO₂—), a C₃₋₁₂ cycloalkyl, a C₂₋₁₂ alkenyl, a C₅₋₁₂cycloalkenyl, a C₆₋₁₂ aryl, a C₇₋₁₃ arylalkylene, a C₄₋₁₂heterocycloalkyl, and a C₃₋₁₂ heteroaryl instead of hydrogen, providedthat the substituted atom's normal valence is not exceeded.

While the invention has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

1. A dual temperature curable silicone composition, comprising: 100parts by weight of a vinyl silicone; 0.05-10 parts by weight of asilicone hydride-containing crosslinker; 0.5-5 parts by weight of aplatinum-containing catalyst; and 0.2-5 parts by weight of a peroxidecatalyst.
 2. The composition of claim 1, wherein the vinyl silicone isof Formula (I):R^(B)[Si(R¹R²)—O]—[(Si(R³R⁴)—O)]_(n)—[Si(R⁵R⁶)—O)]_(m)—Si(R¹R²)—R^(A)  (FormulaI) wherein n has an average value of 1 to 200; m is 0 or has an averagevalue of 1 to 20,000; R^(A), R^(B), R¹, R², R³, R⁴, R⁵ and R⁶ are eachindependently a C₁-C₆ alkyl group; and at least one of R^(A), R^(B), R³and R⁴ has the formula —CH═CR^(F)R^(G), where R^(F) and R^(G) are eachindependently hydrogen or a C₁-C₆ alkyl group.
 3. The composition ofclaim 2, wherein at least one of R^(A), R^(B), R³ and R⁴ is —CH═CH₂. 4.The composition of claim 2, wherein at least one of R^(A) or R^(B) is—CH═CH₂ and R¹ and R² are both methyl groups.
 5. The composition claim1, wherein the vinyl silicone comprises a polydiorganosiloxanefunctionalized with a terminal —Si(Me)₂-CH═CH₂ group; and the siliconehydride-containing crosslinker is of Formula (II):R^(D)—Si(R⁷R⁸)O—[Si(R⁹R¹⁰)—O)]_(x)—[Si(R¹¹R¹²)—O)]_(y)—Si(R¹³R¹⁴)—R^(E)  (FormulaII) wherein at least one of R^(D), R^(E), R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³and R¹⁴ is hydrogen, and the others of R^(D), R^(E), R⁷, R⁸, R⁹, R¹⁰,R¹¹, R¹², R¹³ and R¹⁴ are each independently hydrogen, or C₁-C₆ alkyl; xhas an average value of 1 to 300; and y is 0 or has an average value of1 to
 300. 6. (canceled)
 7. The composition of claim 5, wherein both ofR^(D) and R^(E) are hydrogen and R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, and R¹⁴are methyl.
 8. The composition of claim 5, wherein y is 0; both of R^(D)and R^(E) are methyl; R⁹ is hydrogen and R⁷, R⁸, R¹⁰, R¹³, and R¹⁴ aremethyl.
 9. The composition of claim 5, wherein both of R^(D) and R^(E)are methyl; R⁹ is hydrogen and R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ aremethyl.
 10. (canceled)
 11. The composition of claim 1, wherein theplatinum-containing catalyst comprises a Pt(0) complex, a Pt(II)complex, a Pt(IV) complex, or a combination comprising at least one ofthe foregoing; and the peroxide catalyst comprises an organic peroxide;an aliphatic peroxide; an aromatic peroxide; an organic hydroperoxide;or a combination comprising at least one of the foregoing. 12.(canceled)
 13. The composition of claim 11, wherein the peroxidecatalyst comprises benzoyl peroxide; di-t butyl peroxide;2,4-dichlorobenzoyl peroxide; or2,5-bis(t-butylperoxy)-2,5-dimethylhexan.
 14. The composition of claim1, wherein the platinum-containing catalyst and peroxide catalyst arepresent in a weight percent ratio of 0.001:1 to 1:1.
 15. (canceled) 16.(canceled)
 17. A method of fully curing a dual temperature curablesilicone composition, comprising: providing a silicone composition ofclaim 1; exposing the silicone composition to a first temperature toactivate the platinum catalyst but not the peroxide catalyst, to form asemi-cured composition; and heating the semi-cured composition to asecond temperature sufficient to activate the peroxide catalyst, to forma fully cured composition.
 18. The method of claim 17, wherein the firsttemperature is below 100° C., and the second temperature is 70° C. to200° C., provided that the second temperature is higher than the firsttemperature.
 19. The method of claim 17, further comprising forming thesemi-cured or fully cured silicone composition into a shape. 20.(canceled)
 21. A method of semi-curing a dual temperature curablesilicone composition, comprising: providing a dual temperature curablesilicone composition comprising a vinyl silicone; a siliconehydride-containing crosslinker; a platinum-containing catalyst; and aperoxide catalyst; exposing the silicone composition to a firsttemperature to activate the platinum catalyst but not the peroxidecatalyst to form a semi-cured composition.
 22. The method of claim 21,wherein the first temperature is below 100° C.
 23. The method of claim21, further comprising forming the curable composition or the semi-curedcomposition into a desired shape.
 24. (canceled)
 25. (canceled)
 26. Amethod of forming a semi-cured article comprising: providing thesilicone composition of claim 1; exposing the uncured composition to afirst temperature to activate the platinum catalyst but not the peroxidecatalyst, to provide a semi-cured composition; and shaping thesemi-cured composition to provide a shaped, semi-cured article.
 27. Amethod of forming a semi-cured article comprising: shaping the siliconecomposition of claim 1; and exposing the shaped uncured composition to afirst temperature to activate the platinum catalyst but not the peroxidecatalyst, to provide a shaped, semi-cured article.
 28. A method offorming an article comprising: providing the silicone composition ofclaim 1; exposing the uncured composition to a first temperature toactivate the platinum catalyst but not the peroxide catalyst, to providea semi-cured composition; shaping the semi-cured composition to providea semi-cured article; and heating the semi-cured composition to a secondtemperature sufficient to activate the peroxide catalyst, to form afully cured article.
 29. A method of forming an article comprising:shaping the silicone composition of claim 1 to form an uncured article;exposing the uncured article to a first temperature to activate theplatinum catalyst but not the peroxide catalyst, to provide a semi-curedarticle; and heating the semi-cured article to a second temperaturesufficient to activate the peroxide catalyst, to form a fully curedarticle.
 30. The method of claim 26, wherein the first temperature isbelow 100° C., and the second temperature is 70° C. to 200° C., providedthat the second temperature is higher than the first temperature. 31.The method of claim 26, wherein the shaping comprises casting orcalendering to form a layer.
 32. The method of claim 26, furthercomprising forming the layer on a substrate, wherein the substrate hasbeen treated with a a vinyl tris(alkoxyalkoxy)silane primer.
 33. Themethod of claim 32, wherein the vinyl tris(alkoxyalkoxy)silane is thevinyl tris(alkoxyalkoxy)silane is vinyl tris[(C₁-C₆ alkoxy C₁-C₆alkoxy)]silane is present in an amount of 2-20 parts by weight. 34.(canceled)
 35. The method of claim 26, wherein the second temperature isachieved by laminating the article.